Court records are available as a matter of public record in all the counties surrounding you. I have persoally seen close to 100 lawsuits & filings over the last 10yrs. or so. If you have a lawyer, he can check things out for you. They also have several corporate identities, so your lawyer needs to know that too. Principals of the company now live in N. carolina & Florida. They have been trying to sell the companies in MI. for over a year. Sounds like they would abandon ship if they could.
Again, other pool contractors likely will be able to provide the customers you really need to speak with to make an informed selection of pool co.